Medical balloons have been used in a number of different applications including dilation of bodily vessels and expansion of medical devices such as stents. In the former application, the medical balloon is delivered on a catheter to a stricture in a vessel and expanded to open the stricture. Expansion of the balloon compresses any plaque present at the stricture. In the latter application, a stent, stent-graft, graft or other prosthesis disposed about a medical balloon may be delivered on a catheter to a desired location in a bodily vessel and expanded by inflating the balloon.
In delivering the medical balloon to the desired bodily location, the catheter must traverse tortuous bodily vessels. Typically, a guidewire will be used to facilitate delivery of the catheter to the desired bodily location. In the case of an over-the-wire (OTW) catheter, for example, the guidewire is positioned within a lumen of an over-the-wire catheter with the distal tip of the guidewire just proximal to the distal tip of the catheter. The catheter and guidewire are advanced through a guiding catheter to the distal end thereof. The guidewire is then advanced out of the distal end of the guiding catheter into the patient's coronary vasculature until the distal end of the guidewire crosses the desired location in the vessel. The catheter is next advanced out of the guiding catheter until the catheter balloon is properly positioned.
To facilitate delivery of the balloon, it has proven advantageous to apply lubricious coatings to various portions of the medical balloon and other components of the catheter including the various tubes that form the catheter.
Although the use of lubricious coatings has proven beneficial, the presence of such coatings may, in certain cases, result in “watermelon seeding”. Where a highly lubricious balloon and a highly lubricious outer shaft is used, the balloon may slip from the constraints of the lesion as the balloon is inflated. “Watermelon seeding”, as the slippage is known, can result in inaccurate vessel dilation or inaccurate placement of the stent or other prosthesis. To avoid this, the balloon must be repositioned, adding to the time required by the procedure.
Where the balloon remains fixed in place, another problem which may be encountered involves sliding of a guidewire relative to the balloon.
There remains a need for inventive catheter designs which are not plagued by the problem of “watermelon seeding” and for inventive catheters which do not experience slippage of the guidewire. More generally, there remains a need for inventive balloon catheters which do not experience undesired motion upon inflation of the balloon.
All US patents and applications all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
Without limiting the scope of the invention, a brief summary of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
A brief abstract of the technical disclosure in the specification is provided as well for the purposes of complying with 37 C.F.R. 1.72.